Discrete Diffusion for Bundle Construction

ICLR 2026 Conference SubmissionAnonymous Authors
Bundle ConstructionBundle CompletionRecommendation SystemDiscrete Diffusion Model
Abstract:

As a central task in product bundling, bundle construction aims to select a subset of items from huge item catalogs to complete a partial bundle. Existing methods often rely on the sequential construction paradigm that predicts items one at a time, nevertheless, this paradigm is fundamentally unsuitable for the essentially unordered bundles. In contrast, the non-sequential construction paradigm models bundle as a set, while it still faces two dimensionality curses: the combination complexity is exponential to the catalog size and bundle length. Accordingly, we identify two technical challenges: 1) how to effectively and efficiently model the higher-order intra-bundle relations with the growth of bundle length; and 2) how to learn item embeddings that are sufficiently discriminative while maintaining a relatively smaller search space other than the huge item set.

To address these challenges, we propose DDBC, a Discrete Diffusion model for Bundle Construction. DDBC leverages a masked denoising diffusion process to build bundles non-sequentially, capturing joint dependencies among items without relying on certain pre-defined order. To mitigate the curse of large catalog size, we integrate residual vector quantization (RVQ), which compresses item embeddings into discrete codes drawn from a globally shared codebook, enabling more efficient search while retaining semantic granularity. We evaluate our method on real-world bundle construction datasets of music playlist continuation and fashion outfit completion, and the experimental results show that DDBC can achieve more than 100% relative performance improvements compared with state-of-the-art baseline methods. Ablation and model analyses further confirm the effectiveness of both the diffusion backbone and RVQ tokenizer, where the performance gain is more significant for larger catalog size and longer bundle length. Our code is available at https://anonymous.4open.science/r/DDBC-44EE.

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This report is AI-GENERATED using Large Language Models and WisPaper (A scholar search engine). It analyzes academic papers' tasks and contributions against retrieved prior work. While this system identifies POTENTIAL overlaps and novel directions, ITS COVERAGE IS NOT EXHAUSTIVE AND JUDGMENTS ARE APPROXIMATE. These results are intended to assist human reviewers and SHOULD NOT be relied upon as a definitive verdict on novelty.
NOTE that some papers exist in multiple, slightly different versions (e.g., with different titles or URLs). The system may retrieve several versions of the same underlying work. The current automated pipeline does not reliably align or distinguish these cases, so human reviewers will need to disambiguate them manually.
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Overview

Overall Novelty Assessment

The paper proposes DDBC, a discrete diffusion model for bundle construction that generates bundles non-sequentially via masked denoising. It resides in the 'Discrete Diffusion and Denoising Models' leaf under 'Generative and Diffusion-Based Bundle Construction'. Notably, this leaf contains only the original paper itself—no sibling papers were identified in the taxonomy. This suggests the application of discrete diffusion to bundle construction represents a relatively sparse or emerging research direction within the broader field of partial bundle completion.

The taxonomy reveals that the broader 'Generative and Diffusion-Based Bundle Construction' branch includes a sibling leaf on 'Multimodal and Cross-Category Feature Learning', which houses two papers focusing on multimodal features and item-level feedback. Meanwhile, neighboring branches address 'Matching and Recommendation for Incomplete Bundles' (six papers across three leaves) and 'Decision and Optimization Frameworks for Bundle Selection' (five papers). The scope note for the parent category explicitly excludes deterministic matching and clustering methods, positioning DDBC's probabilistic generative approach as distinct from optimization-driven or retrieval-based techniques prevalent elsewhere in the taxonomy.

Among sixteen candidates examined, the contribution-level analysis shows mixed results. The core non-sequential diffusion mechanism (Contribution A) examined five candidates with no clear refutations, suggesting relative novelty in applying masked discrete diffusion to bundle tasks. However, the residual vector quantization for item embedding compression (Contribution B) examined ten candidates and found one refutable overlap, indicating prior work on embedding compression techniques. The integrated DDBC framework (Contribution C) examined one candidate without refutation. These statistics reflect a limited search scope—top-K semantic matches plus citation expansion—not an exhaustive survey of all relevant literature.

Given the sparse taxonomy leaf and the limited search scale, the work appears to introduce a relatively fresh angle on bundle construction through discrete diffusion, though the embedding compression component has more substantial prior art. The analysis covers a focused set of candidates and does not claim completeness; broader or domain-specific searches might reveal additional overlaps or confirm the novelty observed here.

Taxonomy

Core-task Taxonomy Papers
50
3
Claimed Contributions
16
Contribution Candidate Papers Compared
1
Refutable Paper

Research Landscape Overview

Core task: bundle construction from partial bundles. The field encompasses diverse approaches to assembling complete structures from incomplete or fragmented inputs, spanning generative modeling, recommendation systems, optimization frameworks, and geometric methods. At the top level, the taxonomy reveals several major branches: Generative and Diffusion-Based Bundle Construction leverages probabilistic models to synthesize bundles from partial data; Matching and Recommendation for Incomplete Bundles focuses on pairing or suggesting items when user preferences or item features are missing; Decision and Optimization Frameworks for Bundle Selection address combinatorial and resource-allocation problems under uncertainty; Geometric and Algebraic Bundle Constructions draw on mathematical structures such as fiber bundles and algebraic topology; Data Reconstruction and Imputation from Incomplete Observations targets statistical completion of missing entries; Computer Vision and Spatial Reconstruction from Partial Data handles 3D scene assembly from sparse views; Software Engineering and System Implementation with Partial Data considers practical deployment challenges; Optimization Methods with Inexact or Partial Information study convergence and robustness when inputs are noisy; and Domain-Specific Applications of Partial Bundle Constructions apply these ideas to healthcare, e-commerce, and other specialized settings. Representative works include Anchors Incomplete Multiview[1] in matching, Partial Bundle Adjustment[25] in vision, and Bundle Inexact Data[35] in optimization. Within this landscape, a particularly active line of work explores generative and diffusion-based techniques for synthesizing bundles when only fragments are available, contrasting with classical optimization and algebraic methods that rely on deterministic constraints. Discrete Diffusion Bundle[0] sits squarely in the Generative and Diffusion-Based branch, specifically within Discrete Diffusion and Denoising Models, emphasizing probabilistic denoising over discrete structures. This approach differs from nearby efforts such as Multimodal Bundle Construction[6], which integrates heterogeneous data modalities, and Bundle Matching Multitask[18], which frames bundle completion as a multi-task learning problem. The trade-offs center on flexibility versus interpretability: diffusion models offer expressive generative power but can be harder to constrain, whereas optimization-based methods like Partial Bundle Minimax[42] provide clearer guarantees at the cost of modeling capacity. Open questions include how to best incorporate domain knowledge into generative processes and how to scale these methods to very large or highly incomplete datasets.

Claimed Contributions

Non-sequential bundle construction via masked discrete diffusion

The authors introduce a masked denoising diffusion process that constructs bundles in a non-sequential manner, avoiding the arbitrary ordering imposed by sequential methods. This approach models bundles as sets rather than sequences, capturing higher-order item relations without following a pre-defined left-to-right order.

5 retrieved papers
Residual vector quantization for item embedding compression

The authors integrate residual vector quantization to discretize continuous item embeddings into hierarchical discrete codes from a shared codebook. This compression technique addresses the dimensionality curse caused by large item catalogs while maintaining semantic information at multiple granularities.

10 retrieved papers
Can Refute
DDBC framework combining discrete diffusion with RVQ tokenization

The authors develop DDBC, a complete framework that combines the masked discrete diffusion backbone with RVQ tokenization to address both technical challenges in bundle construction: modeling higher-order intra-bundle relations and handling large item catalogs efficiently.

1 retrieved paper

Core Task Comparisons

Comparisons with papers in the same taxonomy category

Within the taxonomy built over the current TopK core-task papers, the original paper is assigned to a leaf with no direct siblings and no cousin branches under the same grandparent topic. In this retrieved landscape, it appears structurally isolated, which is one partial signal of novelty, but still constrained by search coverage and taxonomy granularity.

Contribution Analysis

Detailed comparisons for each claimed contribution

Contribution

Non-sequential bundle construction via masked discrete diffusion

The authors introduce a masked denoising diffusion process that constructs bundles in a non-sequential manner, avoiding the arbitrary ordering imposed by sequential methods. This approach models bundles as sets rather than sequences, capturing higher-order item relations without following a pre-defined left-to-right order.

Contribution

Residual vector quantization for item embedding compression

The authors integrate residual vector quantization to discretize continuous item embeddings into hierarchical discrete codes from a shared codebook. This compression technique addresses the dimensionality curse caused by large item catalogs while maintaining semantic information at multiple granularities.

Contribution

DDBC framework combining discrete diffusion with RVQ tokenization

The authors develop DDBC, a complete framework that combines the masked discrete diffusion backbone with RVQ tokenization to address both technical challenges in bundle construction: modeling higher-order intra-bundle relations and handling large item catalogs efficiently.